valence electrons

[issa]

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i am having problems understanding why the answer is A.
why n=3 ?

 

[Decan]

Because Co is a transition element, it loses its 4s electrons first before it starts losing the electrons in the 3d orbital.

Hope that helps!

 

[issa]

Because Co is a transition element, it loses its 4s electrons first before it starts losing the electrons in the 3d orbital.

Hope that helps!

i understand that but i don't understand why n=3. atoms in period 4 should have n=4. i am confused. 😕

 

[pre-dentalguy]

i am having problems understanding why the answer is A.
why n=3 ?

It is n=3 because the d-orbital is always minus 1 of whatever period it is. For instance, if the transition metal is in period 4 then it's n=3, if the transition metal is period 5 then it's n=4.

Marion

 

[Decan]

The electron config of Co is [Ar] 3d7 4s2...so if you lose valence electrons, you would lose them from the 4s orbital. The outermost electrons are now in the d orbital, which is n=3.

Let me know if this makes sense.

 

[issa]

thanks. it makes sense now.